1. Field of the Invention
This invention relates to a sampler, i.e. a device designed to carry out sampling, that is the introduction of samples into analytical detection system, said sampler comprising a housing for a sample to be analyzed, formed in a support movable from a position in which the sample is received to a position in which it is introduced into the analytical system, under perfect sealing, said housing being provided with at least one fitting tube to introduce an inert gas for sample washing.
2. Description of the Prior Art
Such samplers are already known in the art. A solid or liquid sample to be submitted to analysis for qualitative and quantitative determination of its components is introduced into them and then the sample introduction into the analytical detection system must obviously occur with the warranty that no other substance capable of altering detection and particularly air is introduced. Generally, these samplers are provided with a drum having several seats for samples, which are in turn positioned where each sample contained in its particular seat is injected into said housing, where it remains to be submitted to washing and is then introduced into the detection system. The known systems of this type generally provide ambient air elimination from the whole sampling system, including the drum with its various seats for samples, in such a way as to maintain the whole ambient under the influence of a washing inert gas, which is the same carrier gas as used in the analytical system. This system obviously requires particularly accurate, complex and expensive operations to obtain an environment, including all the samples to be analyzed, where any trace of atmosphere is eliminated. Furthermore, this involves a considerable loss of time, considering the time elapsing between the moment in which the sampler is loaded and the moment in which any trace of atmosphere has been eliminated from the whole unit and analysis can be finally started. In order to overcome these inconveniences, a sampler of the type described above has already been proposed, in an actual embodiment made by Carlo Erba Strumentazione S.p.A., in which a housing for a sample to be analyzed is obtained in a support movable under perfect sealing conditions within a seat, said support being movable to three different positions to receive the sample from the drum receptacles where the samples to be analyzed are contained, to allow sample washing operation and finally to introduce the sample into the analytical system. This embodiment allows to simplify the structure of sampler and also allows to eliminate dead times necessary to completely remove any residue of atmosphere from the sampler. However, this embodiment still shows some inconveniences, particularly due to the need of carrying-out said two-step displacement of removable support, from the position in which it receives the sample, to the position of washing and to the position of sample introduction into the analytical system, these steps being necessarily carried out with the outmost precision and while keeping the unit perfectly sealed to prevent ambient air from entering, even in very samll amounts, the analytical system. Moreover, this known system may give, in some cases, wrong indications due to air entrainment caused by the same movement of movable support.